1. Field of the Invention
The present invention relates to a method of rendering flexible a pipeline laid on the ground or underground, in order to absorb bending of the pipeline and prevent damage when the pipeline yields to a land subsidence or an earthquake. More particularly, the invention relates to a method of rendering an existing pipeline flexible, in which an intermediate portion of a pipe is cut and removed in a ring form, and a pipe joint is inserted in the cutout position and connected to the pipe with a plurality of sleeves interconnected relatively oscillatably in a watertight condition. The invention also relates to a pipe joint suited for executing this method.
2. Description of the Prior Art
In a convention method of rendering an existing pipeline flexible, a pipe joint is inserted in a cutout position of a pipe and connected to the pipe with a plurality of sleeves interconnected relatively oscillatably in a watertight condition.
In the above conventional method, however, opposite ends of the pipe joint tend to become displaced relative to cut ends of the pipe during a connecting operation since the plurality of sleeves are inserted in the cutout position in a condition easily oscillatable relative to one another. Great trouble and efforts are needed to connect the pipe joint to the existing pipe uniformly in the peripheral direction of the pipe.